The energy requirements for batteries are continually increasing, while constraints on volume and mass continue to be present. Further, the demand for safe, low cost and environmentally friendly materials is increasing. These demands and battery specifications cannot be met using traditional lithium-ion battery chemistries. Although lithium-ion batteries have long been optimized and have demonstrated stable energies, these systems are limited by the amount of lithium that can be reversibly inserted and removed from the battery's active material structure.
The requirements for greater performance, safety, low cost and environmentally friendly materials can only be achieved through the development of new battery materials. Researchers have proposed the replacement of the carbon-based anode with tin. Tin alloys with lithium during the charging of the battery. The lithium-tin alloy forms a maximum concentration of 4.4 lithium atoms per tin atom, a concentration which equals a capacity of 993 mAh/g. A traditional carbon-based anode has a theoretical capacity of 372 mAh/g. Therefore, the replacement of traditional carbon-based anode batteries with tin-based anode batteries could result in higher energy capabilities. In addition, other lithium-alloying materials could be considered as a replacement to carbon-based anode batteries. However, research has shown that there are two main issues with the use of a tin-based and other lithium-alloying material anode systems, the first being a poor cycle life and the second being a poor utilization of the tin. Therefore, there is a need for an improved lithium battery that exhibits increased energy density with adequate cycle life and proper utilization of the battery materials.